Methods and systems for irrigation and climate control

ABSTRACT

Methods and systems are provided for monitoring and controlling irrigation and climate conditions in landscapes (such as, e.g., municipal parks, gardens, and sports fields) and agricultural environments (such as, e.g., open agricultural fields, greenhouses, and other sites growing crops).

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from U.S. Provisional Patent Application No. 61/500,392 filed on Jun. 23, 2011 and entitled METHODS AND SYSTEMS FOR IRRIGATION AND CLIMATE CONTROL, which is hereby incorporated by reference.

BACKGROUND

The present application relates generally to methods and systems for monitoring and controlling irrigation and climate conditions in landscapes (such as, e.g., municipal parks, gardens, and sports fields) and agricultural environments (such as, e.g., open agricultural fields, greenhouses, and other sites growing crops).

BRIEF SUMMARY

A web-based remote monitoring and control system is provided in accordance with one or more embodiments for monitoring environmental, soil, or climate conditions and controlling irrigation or climate control systems at an agricultural or landscape site. A wireless sensor network comprising a plurality of sensor nodes monitors environmental, soil, or climate conditions and controls one or more irrigation or climate control systems at the site. The remote monitoring and control system communicates with the wireless sensor network over a communications network to receive data from and control operation of the sensor nodes. The system can be accessed by personal computers, mobile devices, and other client devices operated by end-users. These devices communicate over a communications network with the system. The system transmits data to and receives remote control commands or queries from end-users.

Users can remotely control irrigation or climate control systems at an agricultural or landscape site. The system provides a user interface displaying the information by customizable windows (portlets on a dashboard) in one page (a dashboard) or at multiple respective pages. The system provides quick access to charts, reports, maps and gives the end user flexibility with various add/remove/edit options.

Various embodiments of the invention are provided in the following detailed description. As will be realized, the invention is capable of other and different embodiments, and its several details may be capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not in a restrictive or limiting sense, with the scope of the application being indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a web-based remote monitoring and control system in accordance with one or more embodiments.

FIG. 2 is a flowchart illustrating an exemplary user login process flow in accordance with one or more embodiments.

FIG. 3 is a flowchart illustrating an exemplary customizable dashboard page display/edit process flow in accordance with one or more embodiments.

FIG. 4 is a flowchart illustrating an exemplary chart create/edit/display process flow in accordance with one or more embodiments.

FIG. 5 is a flowchart illustrating an exemplary crop health monitor process flow in accordance with one or more embodiments.

FIG. 6 is a flowchart illustrating an exemplary degree days calculation process flow in accordance with one or more embodiments.

FIG. 7 is a flowchart illustrating an exemplary report creation process flow in accordance with one or more embodiments.

FIG. 8 is a flowchart illustrating an exemplary data repair process flow in accordance with one or more embodiments.

FIG. 9 is a flowchart illustrating an exemplary notepad usage process flow in accordance with one or more embodiments.

FIG. 10 is a flowchart illustrating an exemplary site or station map usage process flow in accordance with one or more embodiments.

FIG. 11 is a flowchart illustrating an exemplary control process flow in accordance with one or more embodiments.

FIG. 12 is a flowchart illustrating an exemplary irrigation alert process flow in accordance with one or more embodiments.

FIGS. 13-57 are exemplary screenshots illustrating various aspects of the remote monitoring and control system user interface in accordance with various embodiments.

DETAILED DESCRIPTION

In accordance with one or more embodiments, a web-based remote monitoring and control system is provided for monitoring environmental, soil, or climate conditions and controlling irrigation or climate control systems at an agricultural or landscape site. The system includes a wireless sensor network at each site including a plurality of sensor nodes for monitoring environmental, soil, or climate conditions and controlling one or more irrigation or climate control systems at the site. The remote monitoring and control system can be accessed by users operating client devices such as personal computers and mobile devices over a communications network. Users can use the system for receiving data from and transmitting remote control commands or queries to the system. The web-based remote monitoring and control system communicates with the wireless sensor network over a communications network. The system receives data from and controls operation of the sensor nodes.

A web-based remote monitoring and control system user interface in accordance with one or more embodiments can include one or more of the following features:

-   Main Dashboard (containing summary information in portlets or     windows)     -   Quick access to the current site status (forecast, temperature,         humidity, degree days etc.)     -   Charts     -   Crop health monitors     -   Readings     -   Events (e.g. control events)     -   Alerts     -   Pump status monitoring     -   Farm management and information (e.g. budget and yield status)     -   Soil nutrient status     -   Irrigation status/activity (show flow status, show valve status)     -   Notes     -   Maps (shows irrigation zones, soil status with color         indicators—e.g. blue for wet, red for dry and green for normal)     -   Station/sensor status -   More detailed information in respective pages, which can be accessed     through the dashboard     -   Data charts     -   Crop health monitors     -   Readings     -   Event     -   Alerts     -   Pump status monitoring     -   Farm management and information (e.g., budget and yield status)     -   Soil nutrient status     -   Irrigation status     -   Reports     -   Maps     -   Degree Days     -   Control Elements & Conditions     -   Monitoring Elements & Irrigation Alerts -   Switchable screen configuration:     -   Mobile user interface     -   Classic personal computer screen user interface

FIG. 1 illustrates the architecture of an exemplary web-based remote climate monitoring and control system for an irrigation/climate control site (e.g., greenhouse, open field, or landscape) 1 in accordance with one or more embodiments. The system can be accessed by users using various client devices such as, e.g., a mobile device 6 or personal computer 5. The system includes a wireless sensor network 2 having a plurality of sensor nodes installed in the site. The sensor network 2 includes sensor nodes, which form an ad-hoc (i.e., dynamic) wireless sensor network and monitor climate, environmental, and soil conditions, and to collect measurements. The sensor nodes send these measurements to a central computer server 4 through a communications network 3 such as a cellular network (e.g., GPRS, Edge, UMTS etc.) or a wireless wideband network (e.g., WiMAX). Users can communicate with the central server system 4 through a network such as the Internet 7 or a combination of networks, not only to gather the site information but also to configure the user interface according to the user settings stored on the server.

FIG. 2 illustrates an exemplary end-user login flow to the web-based monitoring system. When the end user enters the username and password at the login page, a login check is performed on the server side, comparing with the information on the central database server as shown in step (A1). Login check can include: username and password match check, and user status check (active, inactive, blocked, expired). If the user is valid, the end-user can enter the system and display the accessible sites for that user by switching between sites as shown in step (A3). The end-user can also switch between mobile and classic look of the pages as shown in step (A2). Users can display/change site/user data through main dashboard or at the respective pages as shown in step (A4). They can exit any time (A5), and after the logout confirmation page (A6) return to the login page (A7).

FIG. 3 illustrates an exemplary main dashboard page process flow for all users. This customized page includes user added charts, readings, events, alerts, field and sensor status windows. The current field status window (portlet) gives the user quick access to the most important data from the site such as temperature, humidity, degree days, dew point, and ET (Evapotranspiration) values along with the live forecast info for that site by its zip code as shown in step (B1), FIG. 13, and mobile screen view FIG. 15 are exemplary dashboard screen shots. Users can display this portlet for the selected stations and degree days definitions as shown in steps (B2 and B3) and exemplary FIG. 16. Clicking on the degree days configuration link makes it very easy to access the details and will take the user to the degree days calculation page. All portlets can be minimized. Current field status portlet is minimized in FIG. 14. FIG. 6 describes the details for degree days calculation.

A Notes window shows the last edited notes by the users or the administrators for that site. Users can add or delete notes on the main page (dashboard) as shown in step (B4) and FIG. 13. Clicking on “More” button makes it very easy to access the note details and takes the user to the notepad as shown in step (B5) and exemplary FIG. 41. FIG. 9 describes the details for note creation and usage.

Users can add as many charts to the main page as they want as shown in step (B6) and FIG. 13 and FIG. 57. Clicking on edit lets the user add the predefined charts to the dashboard as shown in step (B7) and exemplary FIG. 17. Clicking on the charts makes it very easy to access chart details and takes the user to the charts page in static mode as shown in step (B8) and exemplary FIG. 19. FIG. 4 describes the details for charts.

Users can display last alert events, control events, and water events in respective windows as shown in steps (B9, B10, B11, B12, B13, B14) and FIG. 14. Clicking on “More” buttons takes the user to the respective event detail pages.

Last readings for selected stations can be viewed in another window as shown in step (B15) and FIG. 14. Users can change the station to be viewed on the edit menu (B16) and go to reading details page by clicking “More” button (B17).

Crop health information is important to the user to see on the main page. Predefined health monitors' summaries for pest and diseases are listed on the portlets at step (B18) and FIG. 14. Clicking on any data will open the crop health monitor configuration page at step (B19). FIG. 5 describes the details for crop health monitors.

Station status displays the reading success percentage for the stations, their battery usage, and signals. In addition to those temperature and humidity are displayed on the same table as shown in step (B21), FIG. 13 and FIG. 57. Irrigation portlet is a quick way to display the irrigation status (B20) as shown in exemplary FIG. 46. Other status portlets are farm management and information, pump status, and soil nutrient status (B22, B23, B24).

Refresh link is to refresh the windows on the dashboard instead of refreshing the entire page. All the windows can be moved to another position by clicking on the banner of the window and dragging to the new position. The windows can be minimized or closed. These are shown in step (B25).

Switching between mobile look and classic look can be done by clicking the switch link at the left bottom corner of the page as shown in step (B26).

FIG. 4 illustrates the chart creation, configuration flow for the web-based remote monitoring system. From Data, charts menu, users can open the charts added before as shown in steps (C1 and C2), or add a new one as shown in step (C3). Charts can be created with preferred styles as bar, square wave, or line charts. Either during new chart addition or displaying an existing chart, users can add new lines to the charts as shown in step (C4) and the exemplary screenshot of FIG. 18. At this step, stations, what data to be read from that station should be selected from the dropdown list. Data lines can include sensor measurement, calculated values based on sensor data, predictions, disease and pest models. Data line's color, label can be changed. Threshold can be viewed either as band (colored in between) or as limit (can be drawn on the chart). Default initial display is visible, but can be changed to hidden. Lines can be removed or the configurations can be changed at any time by the users.

After creating a new one or selecting from the existing chart lists, charts are displayed on the screen as shown in step (C5), the exemplary screenshot of FIG. 19, and the exemplary mobile screen view of FIG. 20. The default display mode is static for all charts (C7). After opening a chart, its view mode can be changed to dynamic by clicking on “Analysis” button at step (C6) and the exemplary screenshot of FIG. 21. In the dynamic mode, the user can move the cursor and see the details as date, time and value of the points on the charts as shown in step (C8). Charts have zoom in and zoom out capabilities. Modes can be switched to static at any time. In step (C9) “Edit” button opens the configuration page for the current chart as shown in exemplary FIG. 22. Time frame can be changed at the configuration page. All changes can be saved and stored in the central database as shown in step (C9). These charts are available to be used in dashboard (classic or mobile), PDF reports, etc. Any changes can be viewed from mobile devices as well. Reloading a chart will refresh the chart with the most recent data from the central database.

FIG. 5 illustrates the crop health monitoring for the web-based remote monitoring and control system. Crop health monitoring can be based on two types: disease and pest. Those types include disease risk indices and pest development stages based on non-proprietary models. These crop, disease, and pest kinds can be added by the system administrators at step (D1) as shown in exemplary FIG. 23. In step (D2) new crop health monitors can be created by clicking on the plus sign at the top right corner of the crop health monitor lists. Start date, name, the crop from the dropdown list and monitoring type should be defined as shown in exemplary FIG. 24. Gear icon at the beginning of the crop monitor's name takes the user to the configuration page to change the settings at step (D6). In step (D3) clicking on the name displays the monitor in any kind of chart with all different risk level zones shown in different colors as shown in step (D4), exemplary FIG. 25. In both cases (charts and table data), disease or pest summary information is displayed on top of the page as it has the same capability on the dashboard. Disease monitors have risk level (severe, high, medium) color codes next to their names as shown in FIG. 24. Pest type monitors has the charts with the last stage zones colored as shown in exemplary FIG. 26. In step (D5), users can choose to see the raw data in a table by clicking on the table sign on the top right corner of the monitor as shown in FIG. 27. FIG. 28 shows the mobile screen for a pest type crop health monitors and FIG. 29 displays the dashboard with crop health monitor on a mobile phone.

FIG. 6 illustrates the degree days calculation process flow for the web-based remote monitoring system. A degree day is a measure of heating or cooling. Totalized degree days from an appropriate starting date are used to plan the planting of crops and management of pests and pest control timing. Users can add new degree day calculations at step (E1) by clicking on the plus sign at the top right corner as shown in exemplary FIG. 31. Temperature reading and station should be defined in the process of degree day creation. Minimum and maximum thresholds, and time frame are used in the calculations. The gear icon at the beginning of the degree days calculations' name takes the user to the configuration page to change the settings at step (E5). In step (E2) clicking on the name displays the calculations in any kind of chart as shown in step (E3), exemplary FIG. 30. In step (E4), users can choose to see the raw data in a table by clicking on the table sign on the top right corner of the degree day calculation as shown in FIG. 32. FIG. 33 shows the mobile phone screen with the degree days calculation table. Users can always return to the graph by clicking on the return sign at the right top corner of the table.

FIG. 7 illustrates the report creation process flow for the web-based remote monitoring system. At step (F1), as shown in exemplary FIG. 34, reports can be displayed from the list on left hand side of the screen or a new one can be created by clicking on the “New” button at the bottom of the report list. During the creation of a new report, reading type should be defined by selecting from the reading drop down list at step (F2). Reports will be created based on the entered time frame at step (F3). The user defines the station from which the reading will be read or reports can be created for the entire site at step (F4). Users can add their predefined charts described at FIG. 4 to the reports at step (F5). These steps are done as shown in FIG. 34. After specifying the details of the report, it can be saved, shown on the screen, printed, or exported to a PDF file at step (F6) as shown in exemplary FIG. 35 (personal computer screen) and in exemplary FIG. 36 (mobile phone screen). These reports can be distributed to more than one recipient at the specified time of the preferred days of every week or one day of every month at step (F7) as shown in exemplary FIG. 37. Reports may have multiple distributions with different recipients at different times.

FIG. 8 illustrates the data repair process flow for the for the web-based remote monitoring system. On the repair criteria window, user can find the measurement data for a specific sensor on the given date at step (G1) as shown in exemplary FIG. 38. When the user enters the information and hits the “Find” button, “Data” window will display the data table at step (G2). When a row is selected on the table, a third window “Data Repair” will be shown to change the selected data at step (G3). The selected row data can be changed with the previous value, next value, average value, or a new value entered by the user at step (G4) as shown in FIG. 38.

FIG. 9 illustrates the note creation process flow for the for the web-based remote monitoring system. Users can either open a note from the list by clicking on the name of the note or create a new one by clicking the plus sign on top right corner of the list window at step (H1). The note list screen can be expanded by the down arrow on the “List of Notes” window. User can select the category based notes, last specified number of nodes by clicking the radio buttons, or do an advanced search by “special filter” option at step (H2) as shown in exemplary FIG. 41. The notes can be sorted by date or importance. Clicking “List” button will change the note list shown right after the search window. During new note creation, note category can be set optionally, station is assigned, and related files may be attached at step (H3). At step (H4), note details will be shown in a new window. The default screen shows only the note text. There is a link “More” for more details. At step (H6), the station, category, reading type, date, author, importance (high, medium, low), and privacy (public, private) can be changed by clicking on “Modify” button. If needed, a screenshot, or any document can be added to the note at step (H5). User can always switch to the “only text” screen by clicking on the “Less” link. Notes can be saved or deleted by the user. User can display or edit the notes through mobile phones as shown in FIGS. 39-40.

FIG. 10 illustrates the site/station map usage process flow for the for the web-based remote monitoring system. The system displays the current site map through, e.g., “Google maps” at step (I1) as shown on exemplary FIG. 42. The name of the station is shown when the cursor moves over the stations pivots. “M” button on the left hand side for the stations centers that station on the screen. At step (I2), “R” button displays the last readings from that station as shown in exemplary FIG. 43. “More” button takes the user to the detailed readings page. Top banner of the left hand side includes three buttons (“S”,“R”, and “A”) and a digital clock. At step (13), “A” button displays the last alerts for the current site as shown in exemplary FIG. 44. “R” refreshes the data and the alerts. At step (I4), “S” displays the map with all accessible sites for the current user as shown in FIG. 45. “M” button on the left hand side centers that site on the map, and “Go” switches the current site to the selected one as shown in FIG. 42.

FIG. 11 illustrates the control element and condition management process flow. The system allows users to list and view control elements that define the elements which the controller physically controls (J2) as shown in exemplary FIG. 48 and FIG. 49. After a physical connection made between the controller equipment and the equipment to be controlled (e.g., irrigation valve, pump, heater, cooler, fan etc.), the user defines the control element in the software through step (J5). An exemplary control element definition page is provided in FIG. 47. For a selected control element, users can show defined control conditions (J6), list control event logs (J7) as shown in exemplary FIG. 50, modify the control element (J8) and send manual control commands to the element (J9).Through the control pages, users can also view the manual control history including the log of who turned on/off what and when (J4) and list control conditions (J3). When it comes to control conditions, users can view the details of each control condition (J10) as shown in exemplary FIG. 51 or add new ones (J11). Each control condition is stored on the central server's database as well as the related controller equipment at the site (e.g. field or greenhouse). Each condition can be disabled (J12), modified or deleted (J13). Control condition pages adapt to the device used for simplifying the browsing on a mobile device as shown in exemplary FIGS. 52A-52B.

FIG. 12 illustrates the irrigation alert definition and management process flow. The first step of setting up an irrigation alert is to define monitoring elements such as pressure switches or water flow meters. The purpose of the irrigation alerts is to notify or alert users when an expected (i.e., planned) irrigation activity does or does not occur. Users can list and view details of monitoring elements (K2) as shown in exemplary FIGS. 53, 54A, and 54B. By clicking or tapping on the + sign shown on these pictures, users can define new monitoring elements. Once the monitoring element is defined and the irrigation schedule or the control condition is known, users can add irrigation alerts (K6). Listing and viewing the details of previously created irrigation alerts can be done on the same page as shown in the exemplary FIGS. 55, 56A, and 56B (K3 & K7). Irrigation alerts can be disabled (K8), modified, or deleted (K9).

The remote monitoring and control processes described above may be implemented in software, hardware, firmware, or any combination thereof. The processes are preferably implemented in one or more computer programs executing on a programmable computer (which can be part of the central server system 4) including a processor, a storage medium readable by the processor (including, e.g., volatile and non-volatile memory and/or storage elements), and input and output devices. Each computer program can be a set of instructions (program code) in a code module resident in the random access memory of the computer. Until required by the computer, the set of instructions may be stored in another computer memory (e.g., in a hard disk drive, or in a removable memory such as an optical disk, external hard drive, memory card, or flash drive) or stored on another computer system and downloaded via the Internet or other network.

Having thus described several illustrative embodiments, it is to be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. For example, the screenshots are provided by way of example only, and can be modified in various ways. Such alterations, modifications, and improvements are intended to form a part of this disclosure, and are intended to be within the spirit and scope of this disclosure. While some examples presented herein involve specific combinations of functions or structural elements, it should be understood that those functions and elements may be combined in other ways according to the present disclosure to accomplish the same or different objectives. In particular, acts, elements, and features discussed in connection with one embodiment are not intended to be excluded from similar or other roles in other embodiments.

Additionally, elements and components described herein may be further divided into additional components or joined together to form fewer components for performing the same functions. For example, the computer server system may comprise one or more physical machines, or virtual machines running on one or more physical machines. In addition, the central server system may comprise a cluster of computers or numerous distributed computers that are connected by the Internet or another network.

Accordingly, the foregoing description and attached drawings are by way of example only, and are not intended to be limiting. 

What is claimed is:
 1. A remote monitoring and control system for landscape or agricultural environments, each of the landscape or agricultural environments having a sensor network comprising a plurality of sensor nodes for monitoring environmental, soil, or climate conditions and controlling irrigation or climate control systems, the remote monitoring and control system comprising: a server computer system located remotely from the landscape or agricultural environments, said server computer system coupled to the sensor network in each landscape or agricultural environment over a communications network for receiving data from and controlling operation of the sensor nodes in the sensor network, said server computer system also coupled to client devices operated by end-users over a communications network for transmitting data to and receiving remote control commands or queries from the end-users for respective sensor networks; wherein said server computer system provides a configurable user interface to the end-users, said user interface comprising a dashboard having a plurality of separate windows that can be customized by each end-user to display selected data from the server computer system, said windows being movable by end-users to different positions on the dashboard, wherein settings for dashboards configured by end-users are stored by the server computer system and used in subsequent log-ins by the end-users.
 2. The remote monitoring and control system of claim 1, wherein the windows in a dashboard can be configured to separately display information on current site status, crop health, events, alerts, pump status, farm management, soil nutrient status, irrigation status or activity, notes, maps, or sensor status.
 3. The remote monitoring and control system of claim 2, wherein the information on current site status includes information on whether forecast, temperature, humidity, dew points, evapotranspiration, or degree days.
 4. The remote monitoring and control system of claim 2, wherein the crop health information includes pest and disease information including risk levels, based on the real time measurements collected by sensor nodes and analytical models run by the server computer system, and wherein crop, disease, or pest kinds can be added through a graphical user interface by a system administrator.
 5. The remote monitoring and control system of claim 4, wherein the pest and disease information is displayed graphically and is color-coded to indicate risk level or in a table format as specified by an end user.
 6. The remote monitoring and control system of claim 1, wherein the server computer system communicates with different types of client devices including personal computers and mobile devices, and wherein the server computer system is configured to adapt the dashboard configured by an end-user to the type of client device used by the and-user.
 7. The remote monitoring and control system of claim 6, wherein the dashboard displayed on a mobile device is adapted such that the windows on the dashboard are rearranged in a column format to avoid the need for horizontal scrolling by the end-user and the menu formatted to fit the screen for easy browsing and clicking on links on the mobile device.
 8. The remote monitoring and control system of claim 1, wherein software can be configured by end-users to automatically generate and distribute reports based on data from sensor networks on a periodic basis.
 9. The remote monitoring and control system of claim 8, wherein end-users can create multiple reports with different titles and content that can be distributed to different users with different schedules.
 10. The remote monitoring and control system of claim 1, wherein the server computer system communicates with each sensor network and end-user through the Internet or a cellular network.
 11. The remote monitoring and control system of claim 1, wherein the irrigation or climate systems to be controlled are defined as control elements, and wherein manual control commands and control conditions are entered through the dashboard.
 12. The remote monitoring and control system of claim 11, wherein control conditions are tied into the control elements and either a time or sensor threshold constraint is defined within each condition using the dashboard or pages accessible through the dashboard.
 13. The remote monitoring and control system of claim 11, wherein a manual control command history is stored by the server computer system indicating who turned a control element such as pump or valve on or off, when, for how long and if the operation was successful, said manual control command history can be viewed by an end-user through the dashboard.
 14. The remote monitoring and control system of claim 1, wherein end-users are assigned roles and are only authorized to access certain sites or features.
 15. The remote monitoring and control system of claim 1, wherein irrigation alerts can be defined based on pressure switch or flow meter activity given a time schedule or control condition set by an end-user.
 16. The remote monitoring and control system of claim 1, wherein control elements are tied into monitoring elements including pressure switches or flow meters in an irrigation application, and wherein the monitoring elements are used by the system to verify expected irrigation activity or send alerts for unexpected irrigation activity.
 17. The remote monitoring and control system of claim 1, wherein end-users can configure and store custom growing degree day calculators with different thresholds, time spans, and temperature sensors so that they track multiple degree day activity at the same time.
 18. The remote monitoring and control system of claim 1, wherein end-users can enter notes in the dashboard or in pages accessible through the dashboard using a built-in notepad and attach files to them, wherein said notes can be listed, sorted, and searched through notepad pages and displayed on the dashboard in automated reports, wherein notes stored using mobile devices also store their location's GPS coordinates with the note.
 19. The remote monitoring and control system of claim 1, wherein the dashboard includes chart windows containing charts defined by end-users and saved by the system, wherein said charts can be placed in the automated reports, and wherein when the charts are shown on a mobile device, the size of the chart matches the screen resolution of the mobile device.
 20. The remote monitoring and control system of claim 1, wherein the dashboard displays irrigation status information including current soil moisture status, water bank fullness in percentage, estimated next irrigation, flow meter, pressure switch and/or valve status, and recommendations to the user regarding when and how much water should be applied for each irrigation zone. 